co-sign (verb) — To sign a document jointly with another person, sometimes as an endorsement.
cosign, cosine, co sign all sound exactly like co-sign but have different meanings and spellings. Mixing these up is one of the most common spelling mistakes in English.
co-sign
verb
To sign a document jointly with another person, sometimes as an endorsement.
cosine
noun
In a right triangle, the ratio of the length of the side adjacent to an acute angle to the length of the hypotenuse. Symbol: cos
Full definition →How to Remember the Difference
- → Focus on meaning first — once you know what each word means, the correct spelling follows naturally.
- → Write a test sentence for each word and save it as a reference.
- → When in doubt, look up the definition — if it doesn't match your sentence, switch to the homophone.
Frequently Asked Questions
What is a homophone of co-sign?
cosign, cosine, co sign are homophones of "co-sign". They sound identical when spoken but have different meanings and spellings.
What is the difference between co-sign and cosign?
"co-sign" and "cosign" sound the same but have different meanings. See the definitions above for how to use each correctly.
What is a homophone?
A homophone is a word that sounds exactly like another word but has a different meaning and often a different spelling. Examples include "their / there / they're", "to / too / two", and "co-sign / cosign". Homophones are a common source of spelling and grammar mistakes.
How do I remember the difference between co-sign and cosign?
A good strategy is to memorize a short sentence that uses each word correctly, then recall that sentence when you are unsure. For example, focus on the meaning first — then let the spelling follow from context. Reading and writing regularly also helps these distinctions become automatic.